Swedish Potato Casserole with a Rich Cozy Ultimate Taste

There’s something comforting about a dish that’s simple, creamy, and deeply satisfying. Janssons Temptation is a beloved Swedish casserole that brings all of that to the table with just a handful of ingredients. It layers tender potatoes, sweet sautéed onions, and savory fish, all baked in rich cream.

The result is golden on top, silky inside, and full of flavor without being heavy or fussy. If you love potato gratins, this Swedish version will quickly become a favorite.

Why This Recipe Works

This casserole is built on balance. The cream softens the potatoes and creates a silky sauce, while the onions add gentle sweetness.

The preserved fish provides a salty, savory pop that keeps every bite interesting. A finishing splash of cream and a breadcrumb topping ensure a crisp, golden crust. The technique is straightforward and dependable, so you get consistent results every time.

Ingredients

• 2 pounds (900 g) waxy potatoes such as Yukon Gold, peeled
• 1 large yellow onion, thinly sliced
• 2 tablespoons butter
• 1 can (3.5–4 oz/100–120 g) sprats in brine (Swedish ansjovis), drained and sliced, plus 2–3 tablespoons of the brine
• 1 3/4 cups (400 ml) heavy cream
• 1/4 cup (60 ml) whole milk (optional, to lighten the cream slightly)
• 1/2 teaspoon ground white pepper (or black pepper)
• 1/4 teaspoon fine sea salt (adjust to taste; the sprats are salty)
• 1/3 cup plain breadcrumbs
• 1 tablespoon butter, melted, for topping
• Butter for greasing the baking dish

Note: Traditional Janssons Temptation uses Swedish “ansjovis” sprats, which are spiced and sweet-cured, not the same as Mediterranean anchovies.

If you can’t find them, see the Variations section for substitutes.

Step-by-Step Instructions

1. Preheat and prepare the dish. Heat your oven to 375°F (190°C). Generously butter a medium casserole dish (about 9 x 13 inches or similar volume).
2. Slice the potatoes. Cut peeled potatoes into thin matchsticks (about 1/8 inch thick) or use a mandoline to make thin batons. Rinse quickly in cold water and pat dry to remove excess starch.
3. Soften the onions. In a skillet over medium heat, melt 2 tablespoons butter.Add sliced onions and cook 6–8 minutes until soft and lightly translucent, not browned. Season with a pinch of salt and white pepper.
4. Layer the casserole. Spread one-third of the potatoes in the dish. Top with half the onions and half the sliced sprats.Repeat with another third of the potatoes, the remaining onions and sprats. Finish with the last third of potatoes.
5. Season and moisten. Drizzle 2–3 tablespoons of the sprat brine over the layers for extra flavor. Whisk cream and milk together with white pepper and a small pinch of salt.Pour evenly over the potatoes. The liquid should just come up to the top layer.
6. Add the crunchy top. Mix breadcrumbs with 1 tablespoon melted butter until sandy. Sprinkle evenly over the surface.
7. Bake until tender. Cover loosely with foil and bake 30 minutes.Remove foil and bake another 25–35 minutes, until the top is golden and the potatoes are tender when pierced. If the top browns too quickly, tent with foil.
8. Rest before serving. Let the casserole sit 10–15 minutes. The cream will thicken slightly, making it easier to serve clean slices.

How to Store

• Refrigerate: Cool completely, then cover and store for up to 3 days.
• Reheat: Warm in a 325°F (165°C) oven, covered, for 15–20 minutes.Uncover for the last few minutes to re-crisp the top.
• Freeze: Not ideal due to the cream and potatoes, which can turn grainy. If you must freeze, wrap tightly and reheat gently, understanding the texture may change.

Benefits of This Recipe

• Simple pantry staples: Potatoes, onions, cream, and a small can of sprats are easy to keep on hand.
• Big flavor, minimal effort: Layering and baking do most of the work. No complicated techniques.
• Perfect for gatherings: It’s a crowd-pleaser and pairs with roast meats, salads, or holiday spreads.
• Make-ahead friendly: Assemble a few hours in advance, then bake when needed.
• Comforting and elegant: It feels special but stays cozy and familiar.

Common Mistakes to Avoid

• Using the wrong fish: Don’t swap in standard Mediterranean anchovies one-for-one.They’re much saltier and lack the sweet-spiced profile of Swedish sprats.
• Cutting potatoes too thick: Thick slices take longer to cook and can stay firm in the middle. Aim for thin batons.
• Skipping the rest: Serving straight from the oven can make the casserole runny. Resting helps the sauce set.
• Over-salting: The sprats and their brine are salty.Season lightly and taste the cream mixture before pouring.
• Dry top, soupy bottom: Make sure the cream level just reaches the top layer of potatoes. Too much or too little liquid affects texture.

Variations You Can Try

• If you can’t find Swedish sprats: Use a mix of finely chopped Mediterranean anchovies and a touch of sugar with a pinch of allspice to mimic the sweet-spiced flavor. Start with 1–2 teaspoons anchovy, 1/2 teaspoon sugar, and a pinch of allspice, then adjust.
• Onion upgrade: Add a small leek (white and light green parts), sliced and softened with the onions for an extra sweet, mellow note.
• Herb hint: A whisper of fresh dill or chives on top after baking adds freshness without overpowering the classic taste.
• Gluten-free topping: Swap breadcrumbs for crushed gluten-free crackers or omit the crumbs and rely on extra baking time for a browned top.
• Richer or lighter: For richer results, use all cream.For lighter, use half-and-half or a 60/40 cream-to-milk blend, but avoid going too light or the sauce may split.
• Cheese: Traditionally, there’s no cheese. If you must, add a very small amount of mild, creamy cheese like fontina under the breadcrumbs. Keep it subtle.

FAQ

What exactly are Swedish “ansjovis” sprats?

They’re small sprats cured in a lightly sweet, spiced brine.

Despite the name “ansjovis,” they’re not the same as Mediterranean anchovies. Their flavor is gentler and slightly sweet, which defines Janssons Temptation.

Can I prepare Janssons Temptation ahead of time?

Yes. You can assemble it up to 6 hours ahead and refrigerate, tightly covered.

Add 5–10 extra minutes of baking time if going into the oven cold. For best texture, add the breadcrumb topping just before baking.

How do I know when it’s done?

The top should be golden and crisp, and a knife inserted in the center should meet little resistance. The cream will be bubbling around the edges.

If the top browns before the potatoes are tender, tent with foil and continue baking.

Do I need to parboil the potatoes?

No. Thinly cut potatoes cook through in the oven. Parboiling can make the casserole too soft and may dilute the flavors.

What can I serve with Janssons Temptation?

It pairs well with roast chicken, pork, or ham, plus a crisp green salad or pickled cucumbers.

For a Swedish touch, serve with a simple beet salad or rye bread on the side.

Can I make it vegetarian?

While it won’t be traditional, you can omit the fish and add umami with a little miso, capers, and a dash of soy sauce or mushroom powder. Keep the seasoning balanced and avoid over-salting.

Why is my casserole watery?

Common causes include too much liquid, cutting potatoes too thick, or not letting it rest. Measure the cream, slice thinly, and give it time to set after baking.

In Conclusion

Janssons Temptation is the kind of dish that makes a meal feel warm and inviting.

It’s easy to assemble, rewarding to bake, and rich without being heavy. With a few simple ingredients and the right technique, you’ll have a creamy, golden casserole that’s worthy of any Sunday dinner or holiday table. Make it once, and it will earn a permanent spot in your comfort food rotation.